A gas-liquid distributor, a reactor for synthesizing methyl isobutyl ketone, and a method thereof

Abstract

The present application relates to a kind of gas-liquid distributor, the reactor of synthetic methyl isobutyl ketone and its method, the gas-liquid distributor includes distribution plate, lower liquid hole being opened on the distribution plate, gas down pipe being set in the distribution plate and extending upwards.The gas-liquid distributor with gas down pipe and lower liquid hole is set, avoids using packing to distribute again, ensures that gas-liquid two phases are evenly entered pipe course.The gas-liquid distributor of the present application, simple structure, distribution effect is good.No need to set structured packing and honeycomb packing again, only by the gas-liquid distributor, it can ensure that gas phase and liquid phase feed enter pipe course and flow is uniform.

Description

[0001] Field of study

[0002] This invention relates to reaction equipment for synthesizing methyl isobutyl ketone, and more particularly to a gas-liquid distributor; furthermore, this invention relates to a reactor and method for synthesizing methyl isobutyl ketone. Background Technology

[0003] Methyl isobutyl ketone (MIBK) is an excellent medium-boiling-point solvent with stable chemical properties. It can meet the special requirements of high-grade coatings in terms of solid composition, evaporation rate, leveling properties, coating strength, and appearance. Due to its good solubility, excellent miscibility with other solvents, and suitable boiling point, MIBK has become a major auxiliary solvent for high-grade coatings.

[0004] Currently, the mainstream technology for methyl isobutyl ketone (MBOK) is the one-step acetone process. This process offers advantages such as a short flow path, low investment, high acetone conversion rate, high MBOK selectivity, and low raw material and energy consumption. The acetone condensation and hydrogenation reaction is a gas-liquid-solid three-phase reaction, resulting in a complex reactor structure and high manufacturing requirements. The reactor is a tubular fixed-bed reactor with the heat transfer medium flowing through the tubes. The tubes are fixed to a tube sheet; the reactants pass through the tubes, while the heat transfer medium flows through the shell side. Baffles are installed between the tubes. The reactor operates at a normal pressure of 3.0 MPa and a reaction temperature of 90–130 °C. To ensure uniform material distribution, the upper part of the reactor is sequentially equipped with a distributor, structured packing, and honeycomb; the lower part is a wedge-shaped support plate, with catalyst (as shown in the attached image) loaded inside the tubes and above the support plate. Figure 6 (As shown). However, the distributor design of this reactor is complex.

[0005] Therefore, developing a gas-liquid distributor with a simple structure that enables uniform entry of both gas and liquid phases into the tube side has become an urgent problem for those skilled in the art. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides a gas-liquid distributor with a downcomer and a liquid outlet, which avoids the need for redistribution with packing material and ensures that the gas and liquid phases enter the tube side uniformly.

[0007] One of the objectives of this invention is to provide a gas-liquid distributor.

[0008] The gas-liquid distributor of the present invention includes a distribution plate, a liquid outlet formed on the distribution plate, and a gas descending pipe provided on the distribution plate and extending upward.

[0009] In a preferred embodiment of the present invention, the distribution plate is flat, preferably disc-shaped, and more preferably circular; and / or

[0010] The downdraft pipes are multiple, preferably evenly distributed on the distribution plate; and / or

[0011] The liquid discharge holes are multiple, preferably evenly distributed on the distribution plate, and more preferably located between two adjacent gas discharge pipes.

[0012] In a preferred embodiment of the present invention, the inner diameter of the downdraft is 15–50 mm, preferably 19–44 mm; and / or

[0013] The height of the downdraft is 10-50cm, preferably 20-30cm.

[0014] In a preferred embodiment of the present invention, the shape of the liquid outlet is any one of circular, square, rhomboid, pentagonal, and hexagonal; preferably, the liquid outlet is circular, and the inner diameter of the liquid outlet is 1 to 6 mm, more preferably 0.5 to 5 mm.

[0015] In a preferred embodiment of the present invention, the ratio of the center-to-center distance between two adjacent downdrafts to the inner diameter of the downdraft is 1.2 to 1.5:1; and / or

[0016] The ratio of the center-to-center distance between two adjacent liquid outlets to the inner diameter of the gas downpipe is 1.2 to 1.5:1.

[0017] The second objective of this invention is to provide a reactor for synthesizing MIBK.

[0018] The reactor of the present invention comprises, from bottom to top, a first tube sheet, a heat exchange tube bundle, a second tube sheet, a gas-liquid distributor as described in one of the objectives of the present invention, a feed nozzle disposed on the side wall of the reactor, and a hydrogen feed pipe disposed on the top of the reactor; wherein, the distribution plate of the gas-liquid distributor is horizontally disposed inside the reactor.

[0019] In a preferred embodiment of the present invention, the distance between the distribution plate and the second tube plate is 5 to 150 mm, preferably 50 to 100 mm.

[0020] In a preferred embodiment of the present invention, the heat exchange tube bundle includes a plurality of vertically arranged heat exchange tubes, and the plurality of heat exchange tubes are vertically corresponding to the plurality of liquid outlets.

[0021] In a preferred embodiment of the present invention, a feed baffle is vertically provided between the feed nozzle and the downgassing pipe in the horizontal direction. The outer edge of the feed baffle is fixed to the side wall of the reactor, and its lower edge is higher than the distribution plate. The orthographic projection of the feed baffle on the side wall of the reactor covers the feed nozzle.

[0022] Preferred,

[0023] The vertical distance between the lower edge of the feed baffle and the distribution plate is 1 / 15 to 1 / 2 of the height of the downdraft; and / or

[0024] The horizontal distance between the middle of the feed baffle and the feed nozzle is 1 / 4 to 1 / 4 of the diameter of the feed nozzle.

[0025] The third objective of this invention is to provide a method for synthesizing MIBK.

[0026] The method for synthesizing methyl isobutyl ketone according to the present invention is carried out using the reactor described in the second objective of the present invention; preferably, acetone enters the reactor from the feed nozzle and hydrogen enters the reactor from the hydrogen feed pipe; acetone and hydrogen enter the heat exchange tube bundle from the liquid outlet and the gas downcomer respectively to react and obtain the methyl isobutyl ketone product.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention, by incorporating a gas-liquid distributor with a downcomer and a liquid outlet, avoids the need for secondary distribution using packing materials, ensuring uniform entry of both gas and liquid phases into the tube side. The gas-liquid distributor of this invention has a simple structure and excellent distribution effect. It eliminates the need for structured or honeycomb packing materials; this gas-liquid distributor alone can guarantee uniform flow of both gas and liquid phases into the tube side. Attached Figure Description

[0029] Figure 1 A schematic diagram of the main structure of the gas-liquid distributor, left feed nozzle, right feed nozzle, hydrogen feed pipe and feed baffle as described in one of the objectives of this invention;

[0030] Figure 2 A top view of the distribution plate, downdraft pipe, left feed nozzle, and right feed nozzle in the gas-liquid distributor described for one of the purposes of this invention;

[0031] Figure 3 for Figure 2 A magnified view of part A in the diagram;

[0032] Figure 4 This is a schematic diagram of the main structure of the reactor described in the second objective of this invention;

[0033] Figure 5 This is a partial top view of the heat exchange tubes, the center of the tube bridge, and the second tube sheet in the reactor described for the second objective of this invention.

[0034] Figure 6 This is a schematic diagram of the main structure of a conventional tubular fixed-bed reactor.

[0035] In the diagram, 1-left feed nozzle; 2-right feed nozzle; 3-feed baffle; 4-downflow pipe; 5-distribution plate; 6-hydrogen feed pipe; 7-liquid outlet; 8-heat exchange tube; 9-tube bridge center; 10-second tube sheet. Detailed Implementation

[0036] The invention will now be further described with reference to the accompanying drawings.

[0037] This invention relates to a gas-liquid distributor, comprising a distribution plate 5, a liquid outlet 7 formed on the distribution plate 5, and a gas downcomer 4 disposed on the distribution plate 5 and extending upward. The gas downcomer 4 is vertically disposed on the upper surface of the distribution plate 5. The gas downcomer 4 is vertically connected (i.e., the lower end of the gas downcomer 4 is located on the distribution plate 5 and is a through hole; the upper and lower ends of the gas downcomer 4 are unobstructed, forming a through pipe), serving as a gas phase channel. The liquid outlet 7 is vertically connected, serving as a liquid phase channel.

[0038] Furthermore, such as Figures 1-3 As shown, the distribution plate 5 is flat, preferably disc-shaped, and more preferably circular. A plurality of upwardly extending downdraft pipes 4 are vertically arranged on the upper surface of the distribution plate 5. There are multiple downdraft pipes 4, preferably evenly distributed on the distribution plate 5. Liquid discharge holes 7 are formed on the distribution plate 5 between the downdraft pipes 4. There are multiple liquid discharge holes 7, preferably evenly distributed on the distribution plate 5, and more preferably located between two adjacent downdraft pipes 4.

[0039] To better achieve uniform entry of the gas and liquid phases into the tube, in one preferred embodiment of the present invention, the flow velocity of the gas phase through the downcomer 4 is no greater than 10 m / s, or the pressure drop through the downcomer 4 is no greater than 0.1 kPa. Preferably, the flow velocity of the gas phase through the downcomer 4 is 0.001–10 m / s, more preferably 0.01–5 m / s; or, the pressure drop through the gas phase through the downcomer 4 is preferably 0.01–0.08 kPa. Further, the inner diameter of the downcomer 4 is preferably 15–50 mm, more preferably 19–44 mm. Even further, the height of the downcomer 4 is 10–50 cm, preferably 20–30 cm. The ratio of the center distance between two adjacent downcomers 4 to the inner diameter of the downcomer 4 is 1.2–1.5:1.

[0040] To better achieve uniform entry of the gas and liquid phases into the tube side, in one preferred embodiment of the present invention, the shape of the liquid outlet 7 can be any one of circular, square, rhomboid, pentagonal, or hexagonal. Further, the preferred shape of the liquid outlet 7 is circular, and the preferred inner diameter of the liquid outlet 7 is 1–6 mm, preferably 0.5–5 mm. The area of ​​the liquid outlet 7 is related to the height of the downcomer 4 to ensure uniform entry of the gas and liquid phases into the tube side. It should be noted that... Figure 3 The circular shape of the liquid outlet 7 does not constitute a limitation of the present invention, as long as the area of ​​the liquid outlet 7 is sufficient to ensure that the flow velocity of the liquid phase meets the preset requirements. The flow velocity of the liquid phase through the liquid outlet 7 is 0.1 to 3 m / s, preferably 0.2 to 0.6 m / s. Furthermore, the ratio of the center distance between two adjacent liquid outlets 7 to the inner diameter of the gas downpipe 4 is 1.2 to 1.5:1.

[0041] Figure 4 A reactor incorporating the aforementioned gas-liquid distributor is shown. From bottom to top, the reactor includes a first tube sheet, a heat exchange tube bundle, a second tube sheet 10, the aforementioned gas-liquid distributor, a feed nozzle located on the side wall of the reactor, and a hydrogen feed pipe 6 located at the top of the reactor. The gas-liquid distributor is horizontally positioned within the reactor and located at its upper part. Specifically, the outer edge of the distribution plate 5 is connected to the inner wall of the reactor, and its outer edge is in close contact with the inner wall. The gas phase enters the reactor through the hydrogen feed pipe 6. The feed nozzle includes a left feed nozzle 1 and a right feed nozzle 2, both located at the same height on the side of the reactor and positioned opposite each other. The liquid phase enters the reactor through the left feed nozzle 1 and the right feed nozzle 2. Vertically, the lower edges of both the left feed nozzle 1 and the right feed nozzle 2 are at least as high as the height of the distribution plate 5.

[0042] In the horizontal direction, a feed baffle 3 is vertically installed between the feed nozzle and the downgassing pipe 4. The outer edge of the feed baffle 3 is fixed to the side wall of the reactor, and its lower edge is higher than the distribution plate 5. The orthographic projection of the feed baffle 3 on the side wall of the reactor covers the feed nozzle. Taking the left side as an example, in the horizontal direction, a feed baffle 3 is vertically installed between the left feed nozzle 1 and the downgassing pipe 4 to prevent the liquid phase from entering the gas phase channel from the top surface of the downgassing pipe 4 when it enters the reactor from the left feed nozzle 1. The orthographic projection of the feed baffle 3 on the side wall of the reactor is sufficient to cover the orthographic projection of the left feed nozzle 1 on the side wall of the reactor. Preferably, the feed baffle 3 is arc-shaped, and the position and area of ​​the feed baffle 3 are sufficient to block the nozzle opening of the left feed nozzle 1. In the horizontal direction, the left and right outer edges of the feed baffle 3 are connected to the inner walls of the reactor on the left and right sides of the left feed nozzle 1. Vertically, the upper edge of the feed baffle 3 is higher than the upper edge of the left feed nozzle 1 and higher than the upper edge of the downdraft pipe 4; the lower edge of the feed baffle 3 is lower than the lower edge of the left feed nozzle 1 and lower than the upper edge of the updraft pipe 4; the lower edge of the feed baffle 3 is higher than the height of the distribution plate 5, so that the liquid phase entering from the left feed nozzle 1 falls on the distribution plate 5 and forms a liquid level of a certain height. More preferably, the vertical distance between the lower edge of the feed baffle 3 and the distribution plate 5 is 1 / 15 to 1 / 2 of the height of the downdraft pipe 4, and the horizontal distance between the middle of the feed baffle 3 and the middle of the left feed nozzle 1 is 1 / 4 to 1 / 2 of the diameter of the left feed nozzle 1. It should be noted that the downdraft pipe 4 here refers to the downdraft pipe 4 closest to the left feed nozzle 1. Similarly, the same feed baffle 3 is also provided between the right feed nozzle 2 and the nearest air downpipe 4, and the specific description is the same as the description on the left above.

[0043] In the actual MIBK production process, hydrogen enters the reactor through the hydrogen feed pipe 6. Acetone enters the reactor through both the left feed nozzle 1 and the right feed nozzle 2. Upon entering the reactor, the acetone is deflected by the feed baffle 3, and the liquid phase falls onto the distribution plate 5, forming a certain liquid level and a certain static pressure head. It should be noted that the liquid level is located in the middle of the downcomer 4, and its level is automatically controlled by a flow meter. The liquid acetone moves downwards through the lower liquid hole 7. By appropriately setting the inner diameter of the downcomer 4, the downward flow velocity of hydrogen can be controlled. Similarly, by setting the area of ​​the lower liquid hole 7, the downward flow velocity of acetone can be controlled to match the downward flow velocity of the gas phase. Since the height of the downcomer 4 determines the maximum height of the acetone liquid layer on the distribution plate 5 and the static pressure head formed by the acetone liquid layer, the area of ​​the lower liquid hole 7 can be determined, thus ensuring that the acetone flows downwards uniformly and matches the downward flow velocity of the gas phase.

[0044] The distributor is equipped with a disc-shaped tube sheet, preferably a circular disc; its outer edge is connected to the inner wall of the reactor and is horizontally arranged, with the outer edge of the tube sheet tightly fitted to the inner wall of the reactor. Figure 4 As shown, the tube sheet includes a second tube sheet 10 near the lower edge of the gas-liquid distributor and a first tube sheet near the bottom of the reactor. The first tube sheet and the second tube sheet 10 are uniformly provided with a plurality of through holes to accommodate heat exchange tube bundles. The heat exchange tube bundles consist of a plurality of vertically arranged heat exchange tubes 8. The arrangement of the through holes is the same as the arrangement of the heat exchange tubes 8, allowing the plurality of heat exchange tubes 8 to pass through. The distance between the distribution plate 5 and the second tube sheet 10 is 5–150 mm, preferably 50–100 mm. The inner diameter of the heat exchange tubes 8 is 15–50 mm, preferably 19–44 mm. The ratio of the center-to-center distance between two adjacent heat exchange tubes 8 to the inner diameter of the heat exchange tube 8 is 1.2–1.5:1.

[0045] Each of the multiple heat exchange tubes 8 and the multiple liquid discharge holes 7 are vertically corresponding to one another, and the number of heat exchange tubes 8 is the same as the number of liquid discharge holes 7. Preferably, the liquid discharge holes 7 are coaxially arranged with the heat exchange tubes 8, the inner diameter of the liquid discharge hole 7 is smaller than the inner diameter of the corresponding heat exchange tube 8, and the center of the orthographic projection of the liquid discharge hole 7 on the horizontal plane coincides with the center of the orthographic projection of the heat exchange tube 8 on the horizontal plane. The liquid phase moving downward through the liquid discharge holes 7 drips uniformly into the heat exchange tube 8 located below it.

[0046] The portion of the tube sheet connecting adjacent heat exchange tubes 8 constitutes a tube bridge. For example... Figure 5 As shown, the heat exchange tubes 8 are arranged in a symmetrical triangle. Taking three adjacent heat exchange tubes 8 as an example, connecting the centers of the three heat exchange tubes 8 together forms a triangular region, the center of which is the tube bridge center 9. Preferably, the downdraft pipes 4 can be perpendicularly corresponding to the tube bridge center 9; more preferably, each tube bridge center 9 corresponds to one downdraft pipe 4. That is, the center of the orthographic projection of the downdraft pipe 4 on the horizontal plane coincides with the tube bridge center 9. It should be noted that, since it is relatively easy for the gas phase to change direction, the number of downdraft pipes 4 does not necessarily have to be the same as the number of heat exchange tubes 8, and the center of the orthographic projection of the downdraft pipe 4 on the horizontal plane does not necessarily have to coincide with the tube bridge center 9. The fact that the center of the orthographic projection of the downdraft pipe 4 on the horizontal plane coincides with the tube bridge center 9 is only an exemplary description and does not constitute a new limitation on the present invention. Similarly, Figure 5 The arrangement of multiple heat exchange tubes 8 on the tube sheet is merely an illustrative description and does not limit the arrangement of the heat exchange tubes 8. Other polygonal arrangements are also possible.

[0047] Hydrogen and acetone flow uniformly downwards from the downcomer 4 and the liquid outlet 7, respectively. Acetone enters the heat exchange tube 8, and hydrogen also enters the heat exchange tube 8. This is because, although the center of the downcomer 4's orthographic projection on the horizontal plane coincides with the center of the pipe bridge 9, the pipe bridge obstructs the flow of hydrogen above it, preventing further downward movement. Therefore, this portion of hydrogen changes direction and enters the heat exchange tube 8 near the center of the pipe bridge 9, continuing its downward movement. The downcomer 4 ensures uniform downward movement of hydrogen into the heat exchange tube 8, while the liquid outlet 7 ensures uniform downward movement of acetone from the distribution plate 5 into the heat exchange tube 8, guaranteeing uniform entry of both gas and liquid phases into each heat exchange tube 8. The gas and liquid phases react under the catalysis of the catalyst in the heat exchange tube 8 to produce MIBK.

[0048] Other parts of the reactor for synthesizing MIBK according to the present invention can adopt the conventional design of existing MIBK synthesis reactors.

[0049] Example 1

[0050] In a preferred embodiment of the present invention, an appendix is ​​used. Figures 1-5 The reactor with the gas-liquid distributor shown in the diagram performs a MIBK synthesis reaction. The reactor has a diameter of 1900 mm, and the heat exchange tube bundle contains 1216 heat exchange tubes 8. Each heat exchange tube 8 has an outer diameter of 38 mm, an inner diameter of 32 mm, and a height of 9 cm. The center-to-center distance between adjacent heat exchange tubes 8 is 47.5 mm. The lower end of each heat exchange tube is located within a first tube sheet, and the upper end is located within a second tube sheet 10. A distribution plate 5 of the gas-liquid distributor is located 100 mm above the second tube sheet 10. The distribution plate 5 has 1216 upward-extending downdraft pipes 4, each with an outer diameter of 38 mm, an inner diameter of 32 mm, and a height of 30 cm. The center-to-center distance between adjacent downdraft pipes 4 is 47.5 mm. Each downdraft pipe 4 corresponds perpendicularly to a center 9 of a tube bridge. The distribution plate 5 has 1216 liquid discharge holes 7, each with an inner diameter of 3 mm and a center-to-center distance of 47.5 mm between adjacent holes. Multiple heat exchange tubes 8 are perpendicularly aligned with and coaxially arranged around each of the liquid discharge holes 7. The flow velocity of hydrogen in the downgassing pipe 4 is 0.015 m / s, and the flow velocity of acetone in the liquid discharge holes 7 is 9 m / s. A feed nozzle, consisting of a left feed nozzle 1 and a right feed nozzle 2, is positioned above the distribution plate 5, at the same height on the side of the reactor and facing each other. The diameter of the feed nozzle is 80 mm. Two feed baffles 3 are respectively positioned between the feed nozzle and the downgassing pipe closest to the inner wall of the reactor; the distance between the center of the feed baffle 3 and the feed nozzle is 80 mm. The height of the feed baffle 3 is 30 cm, and the distance between the lower edge of the feed baffle 3 and the distribution plate is 54 mm.

[0051] Comparative Example 1

[0052] like Figure 6 The prior art tubular fixed-bed reactor is shown. The upper part of the reactor is equipped with a liquid-holding distributor, structured packing, and honeycomb in sequence; the lower part of the reactor is a wedge-shaped support plate, and the catalyst is filled inside the tubes and on the support plate. The distributor design of the reactor is complex.

[0053] Compared to the prior art in Comparative Example 1, the gas-liquid distributor structure of Embodiment 1 of the present invention enables the gas and liquid phases to enter the heat exchange tubes more uniformly. This is because the prior art distributors are equipped with random packing and honeycomb packing, which inevitably leads to wall effects and channeling, and the smaller the packing height, the more pronounced the wall effect. The gas-liquid distributor of Embodiment 1 of the present invention ensures a consistent flow rate of liquid phase dripping from each liquid outlet 7 through the uniform distribution of liquid level and static pressure head on the distribution plate 5, thus ensuring a consistent flow rate of liquid phase entering each heat exchange tube 8. At the same time, a downcomer 4 is provided to ensure that the gas phase can pass through the distribution plate 5 uniformly and enter each heat exchange tube 8 uniformly. In Comparative Example 1, the selectivity of the MIBK synthesis reaction is 94%, and the catalyst lifetime is 7200 h. In Embodiment 1, because the gas and liquid phases enter the heat exchange tubes 8 uniformly, the selectivity of the reaction is improved to 94.2%; on the other hand, the hot spot temperature is easier to control, and the reactor is less prone to temperature runaway. Furthermore, the uniform entry of the gas and liquid phases into the heat exchange tube 8 will extend the catalyst's lifespan. In this embodiment, the catalyst's lifespan can reach 8000 hours.

Claims

1. A reactor for synthesizing MIBK, characterized in that: The reactor, from bottom to top, comprises a first tube sheet, a heat exchange tube bundle, a second tube sheet, a gas-liquid distributor, a feed nozzle located on the side wall of the reactor, and a hydrogen feed pipe located at the top of the reactor. The gas-liquid distributor includes a distribution plate horizontally disposed within the reactor, a liquid outlet on the distribution plate, and a downgassing pipe located on the distribution plate and extending upwards. Multiple downgassing pipes are evenly distributed on the distribution plate. Multiple liquid outlets are evenly distributed on the distribution plate. Each liquid outlet is located between two adjacent downgassing pipes. The height of each downgassing pipe is 10-50 cm. Each liquid outlet is circular, with an inner diameter of 0.5-5 mm. The heat exchange tube bundle includes multiple vertically arranged heat exchange tubes, each of which is vertically corresponding to a plurality of liquid outlets; the portion of the tube sheet connecting adjacent heat exchange tubes is a tube bridge, and the adjacent heat exchange tubes are arranged in a angular equilateral triangle, with the center of the triangle formed by the line connecting the centers of three adjacent heat exchange tubes being the center of the tube bridge, and the center of the tube bridge being vertically corresponding to the gas downpipe.

2. The reactor according to claim 1, characterized in that: The distribution plate is flat.

3. The reactor according to claim 2, characterized in that: The distribution plate is disc-shaped.

4. The reactor according to claim 3, characterized in that: The distribution plate is disc-shaped.

5. The reactor according to claim 1, characterized in that: The height of the downdraft is 20-30cm.

6. The reactor according to claim 1, characterized in that: The inner diameter of the downdraft is 15~50mm.

7. The reactor according to claim 6, characterized in that: The inner diameter of the downdraft is 19~44mm.

8. The reactor according to any one of claims 1 to 7, characterized in that: The ratio of the distance between the centers of two adjacent downdrafts to the inner diameter of the downdraft is 1.2 to 1.5:1; and / or The ratio of the center-to-center distance between two adjacent liquid outlets to the inner diameter of the gas downpipe is 1.2 to 1.5:

1.

9. The reactor according to claim 1, characterized in that: The distance between the distribution plate and the second tube sheet is 5~150mm.

10. The reactor according to claim 9, characterized in that: The distance between the distribution plate and the second tube sheet is 50~100mm.

11. The reactor according to claim 1, characterized in that: In the horizontal direction, a feed baffle is vertically provided between the feed nozzle and the downdraft pipe. The outer edge of the feed baffle is fixed to the side wall of the reactor, and its lower edge is higher than the distribution plate. The orthogonal projection of the feed baffle on the side wall of the reactor covers the feed nozzle.

12. The reactor according to claim 11, characterized in that: The vertical distance between the lower edge of the feed baffle and the distribution plate is 1 / 15 to 1 / 2 of the height of the downdraft; and / or The horizontal distance between the middle of the feed baffle and the feed nozzle is 1 / 4 to 1 / 4 of the diameter of the feed nozzle.

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